Catch up on today's top five analyst upgrades with this list compiled by The Fly: 1. Advance Auto Parts (AAP) upgraded to Overweight from Neutral at Atlantic Equities with analyst Sam Hudson saying he expects an inflection in comps and margins when the company reports towards the end of May. 2. Northrop Grumman (NOC) and Harris (HRS) were upgraded to Conviction Buy from Buy at Goldman Sachs. 3. Louisiana-Pacific (LPX) upgraded to Buy from Neutral at DA Davidson with analyst Steven Chercover saying while the oriented strand board prices are near or at their peak, the company's blend of earnings power, balance sheet liquidity, and sales mix offer a "compelling value" at the stock's current price level. 4. Columbia Property (CXP) upgraded to Buy from Neutral at Goldman Sachs with analyst Andrew Rosivach saying he sees an attractive entry point at current share levels. 5. Loma Negra (LOMA) upgraded to Buy from Hold at HSBC and to Overweight from Equal Weight at Morgan Stanley. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.